Cannot Use the History Command

Hi everyone,
I cannot use esc+k to preview history commands, so I check the output of "set -o",it seems OK. But when I tried to use "fc -l" it reported "ksh: fc: no history file". I can find my history file with correct permission:
#ls -l /|grep history
-rw- 1 root system 13000 4?10 13?58 .sh_history
#set -o
Current option settings
allexport off
bgnice on
emacs off
errexit off
gmacs off
ignoreeof off
interactive on
keyword off
markdirs off
monitor on
noexec off
noclobber off
noglob off
nolog off
notify off
nounset off
privileged off
restricted off
trackall off
verbose off
vi on
viraw on
xtrace off
#oslevel -s
6100-06-09-1228

Check $HISTFILE and $HISTSIZE are set correctly, normally /etc/environment. Try touching a temporary file eg. ./history and then export HISTFILE=./history, enter a few commands and see if they are added to the file. Remember you can always check it by cat'ing the file. You should also confirm that your shell is correct:

# echo $SHELL
/usr/bin/ksh

# ps
PID TTY TIME CMD
7536666 pts/0 0:00 ps
9961614 pts/0 0:00 -ksh

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Check your environment with the "env" command and ensure your /etc/environment file is in place. Also check your ~/.profile AND ensure your $PATH is properly set.
Upon login, run "set -o vi" and see if your esc+k works. Maybe you are using a different shell, like bash?
. . . and maybe ask around - someone might have changed your default shell environment.

Check $HISTFILE and $HISTSIZE are set correctly, normally /etc/environment. Try touching a temporary file eg. ./history and then export HISTFILE=./history, enter a few commands and see if they are added to the file. Remember you can always check it by cat'ing the file. You should also confirm that your shell is correct: